1. Field of the Invention
The present invention relates to a catalyst regenerating apparatus for an exhaust cleaning apparatus of an internal combustion engine. More specifically, the present invention relates to controlling an internal combustion engine having a main catalytic converter and a bypass catalytic converter for removal of sulfur poisoning in the catalyst of the bypass catalytic converter.
2. Background Information
Most vehicles with an internal combustion engine are provided with an exhaust cleaning apparatus. One example of a conventional exhaust cleaning apparatus for an internal combustion engine is disclosed in Japanese Laid-Open Patent Publication No. 9-88687. In this publication, the exhaust cleaning apparatus includes a pair of catalytic converters provides in the exhaust system. The exhaust system has an exhaust pipe with a main catalytic converter and a bypass exhaust channel with a bypass catalytic converter. The main and bypass exhaust channels are parallel. A bypass controlling-valve is provided at the branch point of the exhaust pipe and the bypass exhaust channel such that the exhaust is controlled so as to flow into either the exhaust pipe or the bypass exhaust channel.
In this publication, the exhaust flows into the bypass exhaust channel while the internal combustion engine warms up, and the exhaust is cleaned by the bypass catalytic converter provided in the bypass exhaust channel. After warm-up, the exhaust flows into the exhaust pipe, and the exhaust is cleaned by the main catalytic converter provided in the exhaust pipe.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved catalyst regenerating apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.